Attachment for type-writing machines



N. W; HARTWELL & T. J. HOWE.

ATTACHMENT FOR TYPE WRITING MAGHINES. No. 528,092.

Patented Oct. 23, 1894.

351 ("M/mu .U UMTED (STATES NEWTON W. HARTWELL AND THOMAS J. HOWE, OF LOUISVILLE, KENTUCKY.

PATENT @Frrcn.

ATTACHMENT FOR TYPE-WRITING MACHINES.

SPECIFICATION forming part of Letters Patent No. 528,092, dated October 23, 1894. Application filed February 26, 1894. 1 flerial No. 501,579. (No model.)

To all whom it may concern.-

Be it known that we, NEWTON W. HART- WELL and THOMAS J. HOWE, citizens of the United States, residing at Louisville, in the county of Jefferson and State of Kentucky, have invented certain new and useful Improvements in Attachments for Type-Writing Machines; and we do declare the following to present to the eye of the operator the correct image of the characters, simultaneous with the r formation and to indicate by a scale their position on the writing surface.

Inthe drawings which form a part of this appl cation, Figure 1 is a perspective view of our invention applied to the upper portion of the frame of a Remington type-writer, the latter and the platen being shown in dotted lines. Fig. 2 is a view of one part of our device on the line 02-01:, Fig. 1. Fig. 3 is a perspectlve view of the reflecting and refractin g prismoid which constitutes an important part of our invention.

A represents a metal bracket which in this ing through slot 0 in the arms to permit of v the adjustment of the arms when necessary to raise or lower the prismoid D. Pivoted to each arm is a latch e which holds the prismoid when placed in position in the slot "i in the arm 0, by hearing against the pivot d on the prismoid and closing the slot 43.

The prismoid D is composed of flint, crown or plain glass, with faces 1, 2, 3 and 4 and angles which we have found by experiment produce a refractive and reflective result which enables the operator to see in acorrect position the letters as they are formed on the writing surface placed on the platen. When the prismoid is applied to a type-writing machine in a correct position with the rays of incidence falling at approximately right angles with the plane of the face 1, We secure a reflective surface or field of vision in the lower portion of the face 4 from which the rays of emergence are thrown at approximately right angles with said face. This is caused by the rays being bent in passing through the face 1 so that they are inverted on the face 2 from which they are re-inverted on the face 3 so that they appear on the face 4 in their correct or original position. On either end of the prismoid is a metal sleeve (1 with a pivot or pin cl which fits into the slot 41 in the arm 0. To prevent the prismoid from turning on the pivot 61, and at the same time secure the exact adjustment of the prismoid necessary to produce the desired result, the arms G,have their lower and outer ends turned up to form a bearing surface 6 for the prismoid, to hold it at the proper angle. Upon the face 1 of the prismoid is etched or otherwise provided the scale used to indicate. the spacing of the letters on the type-writer.

In applying our device to a type-writer of the form indicated, after looking the prismoid in position between the arms 0 by inserting the pivots d in the slots 2 and pressing down the upper ends of the latches e until their lower ends impinge against the pivot d, the attachment is adjusted to the frame of the machine so that the prismoid is below the platen and just far enough from the point of impression of the type on the writing surface to prevent the type bars from striking the prismoid. The type impression is refracted through the face 4 and reflected from the face 3 in a correct position relative to its shape and to the word or line of which it forms a part, and the operator is enabled to see it without changing position from that commonly taken in the use of the type-writing machine. While in the drawings and in the foregoing description, we have shown our invention as applied to but one form of type-writer it is apparent that the prismoid which we employ may be applied to other forms of machines in which the writing or letter impression is made by the type striking upward against the platen, it being only necessary to modify the bracket or means of adjusting the prismoid to the machine.

We have made separate application for Letters Patent on the peculiar form of the 'prismoid shown in this application the same having been filed July 19, 1893, and serially numbered 480,887.

We are aware that single reflecting surfaces have been used in type-writing machines, which reverse the image reflected therein, and that two reflectors have been used so that the inverted image in the one is shown correctly in the other; and we are also aware that a transparent prism having a refleeting backing or base has been used which shows the image in a correct position. We do not claim broadly any one of these devices.

What we do claim, and desire to secure by Letters Patent, is

An attachment for type-writing machines composed of brackets adj ustably secured to the frame of the machine, arms depending from said brackets and adjustable thereon, and a retracting and reflecting prism rhomboidal in cross section, supported by said arms in the manner and for the purposes set forth.

In testimony whereof we affix our signatures in presence of two witnesses.

NEWTON W. HARTWELL. THOMAS J. HOWE.

Witnesses:

JOHN S. CARPENTER, DAN L. SAUER. 

